Archives

I recently reviewed a book about Carl Sagan’s interest in ancient aliens, written by Donald Zygutis (1). Early on in his illustrious career, Sagan expressed scepticism about seeking E.T. life using radio telescopes, instead advocating a search through historical accounts and myths to determine whether our planet had been visited (2). He argued that in a standard galaxy there are so many stars/planets etc, that all you’d need to do is point the radio receiver at any given galactic source beyond the Milky Way, and alien radio signals should come screaming out at you.

They generally don’t, of course, which led Sagan to the early logical conclusion that SETI’s search with radio telescopes was bound to fail. However, this approach became the only game in town, with serious funding at its disposal, and Sagan fell into line behind it – supporting this doomed search for E.T. radio signals ostensibly from stars within out galactic neighbourhood.

Decades on, and SETI has come up with little of any merit. The odd interesting blip, sure, but nothing demonstrably repetitive, or intelligent. Other searches have also come up empty-handed, including an extensive search for highly advanced galactic civilisations using infra-red (3), based upon the theories of the physicist Freeman Dyson. Looking for an infra-red signature from other galaxies seems like a bit of a stretch to me. Sagan’s initial premise about radio waves emanating from other distant galaxies is more plausible. By staring at the tiny amount of our sky that any given distant galaxy occupies, radio telescopes can cover a lot of possible stars in a very small space. If any of them contain radio-emitting alien species, shouting for attention, then we should pick them up one would have thought. Read More…